Influence of interface notch geometry on the tensile behaviour of FGF-printed parts
Bibliographic record
Abstract
<ns3:p>The paper investigates the influence of interface notches ‒ formed due to extrudate geometry ‒ on the tensile performance of parts manufactured by fused granular fabrication (FGF). Although FGF enables fast, cost-effective, large-scale printing with thermoplastic pellets, its adoption in industry remains limited, mainly due to poor mechanical performance. Interface notches have been identified as a key contributor to this limitation. The study investigates the effect of layer height on notch severity and its impact on the tensile behaviour of PETG samples, to improve understanding and guide process optimisation.Single-extrudate-thick PETG walls were printed at two different layer heights (3 mm and 4.5 mm) using a large-scale pellet-fed 3D printer. Tensile specimens were extracted from these walls and tested using digital image correlation (DIC) to map full-field strain. Interface notch geometry was characterised through optical microscopy and image analysis, focusing on key parameters including notch depth, angle, and root radius. The geometric features were then correlated with the tensile properties and localised strain distribution observed during loading.Increasing the layer height resulted in deeper, sharper interface notches that raised the strain concentration factor and caused more premature failure. The 4.5 mm layer height sample showed a 31% reduction in ultimate stress and a 29% decrease in strain at break compared to the 3 mm sample. DIC analysis confirmed that the strain localised at the notch roots, highlighting the impact of severe notches on tensile performance.Future studies could expand on this work by exploring a wider range of layer heights, nozzle sizes, materials, and interfacial healing conditions. Quantifying the evolution of notch geometry across multiple process variables could help establish predictive models for failure.Understanding the role of notch geometry in FGF-printed parts helps inform optimal printing strategies for improving part strength and reliability. Findings can guide design choices in the structural applications of large-format printing, where the extrudate shape has a significant influence on performance.The paper highlights the often overlooked role of interface notch geometry as a key driver of failure in FGF-printed structures. By combining DIC and quantitative notch characterisation, it offers new insights into the geometric mechanisms behind anisotropy and strength reduction in material extrusion additive manufacturing.</ns3:p>
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".